Automatic pilot control



N. B. MURPHY AUTOMATIC PILOT CONTROL July 25, 1950 3 Sheets-Sheet 1 Y mmm N R EB m mm m w W 38k Filed July 13, 1945 July 25, 1950 NB. MURPHYAUTOMATIC PILOT CONTROL 5 Sheets-Sheet 2 Filed July 15, 1945NofizzanBMzqoky K TORNEY July 25, 1950 N. B. MURPHY 2,516,641

Au'rom'nc PILOT CONTROL Filed July 15, 1945 3 Sheets-Sheet 5 INVENTORNarnia/LB. Man-ply W @ORNEY Patented July 25, 1950 UNITED STATES PATENTOFFICE AUTOMATIC PILOT CONTROL Norman E. Murphy, West Englewood, N. 5.,assignor to Bendix Aviation Corporation, Teterboro, N. J., a corporationof Delaware Application July 13, 1945, Serial No. 604,861-

18 Claims. 1

This invention relates generally to automatic pilot or control systemsfor dirigible craft and more particularly to novel automatic turnprovisions therefor and as such constitutes an improvement over theautomatic turn control unit of copending application Serial No. 585,236,filed May 22, 1945, which, in turn, constitutes a division ofapplication Serial No. 516,489, filed December 31, 1943.

An object of the present invention is to provide a novel, compact andsimple turn control unit for aircraft automatic pilots or the like.

Another object of the invention is to provide a novel turn controlmechanism for an aircraft automatic pilot whereby craft attitude may bechanged while the automatic pilot is engaged.

A further object is to provide a novel turn control unit for an aircraftautomatic pilot whereby in response to manual adjustments of controls onthe front of the unit, pitch, bank and rudder signals can be modifiedand the craft made to execute coordinated maneuvers while with the turnadjustments centered the craft assumes straight fiight.

The above and other objects and advantages of the present invention willappear more fully hereinafter from a consideration of the detaileddescription which follows, taken together with the accompanying drawingswherein one embodiment of the invention is illustrated.

In the drawings, wherein like reference characters refer to likepartsthroughout the several views,

Figure 1 is a diagrammatic illustration of an automatic control systemfor dirigible craft embodying the novel automatic turn control unit ofthe present invention;

Figure 2 is a detailed schematic illustration of the novel turn controlunit of the present invention;

Figure 3 is a front elevation view of one practical embodiment of thecontrol panel for operating the novel turn mechanism of Figure 2; and,

Figure 4 is a side elevation view of the turn panel of Figure 3illustrating the arrangement of the turn, bank and pitch knobs thereon.

Referring now to the drawings for a more detailed description of thepresent invention and more particularly to Figure 1 thereof, it is thereshown as embodied in an all electric automatic pilot providing threeaxes of control, claimed and described more fully in copendingapplication Serial No. 516,488, filed December 31, 1943.

As more fully described in the latter applica-- tion, the control ofrudder 18 as shown in Figure 1, is derived from a gyro stabilized earthinductor type compass l i and a rate of turn gyro pickoff E2. Thecompass includes an inductive coupling device 13 having an angularlymovable rotor I i, a motor 15 for displacing rotor I4, a compass signaltransmitter it, and a magnetic clutch i! for coupling the rotor It withthe signal transmitter under certain conditions. The compass signaltransmitter is connected with the rudder channel of an amplifier t8, theoutput of which energizes a servo motor i9 connected to the rudderthrough a clutch 20. The rate signal of pick-off I2 is also impressed onthe rudder channel of the amplifier through an inductive rateor turnreceiver device i3l, comprising a wound stator 35 and an inductivelycoupled wound rotor I32, arranged within the novel controller unit ofthe present invention, generally designated with the reference character22, to be described more fully hereinafter, Operation of rudder motor 89displaces rudder i5 and also an inductive follow-up device 23 developingin the latter a follow-up signal which is impressed on the rudderchannel of the amplifier to be mixed with the displacement and ratesignals.

Signals for operating aileron and elevator surfaces 24 and 25, on theother hand, are de veloped by bank and pitch take-ofi's 26 and 2'!arranged about the bank and pitch axes of an artificial horizon gyro 28.As a result of a banked condition, take-off 2t developes a bank signalwhich is coupled to the input of the aileron channel of amplifier Itthrough an inductive bank receiver device I41, comprising a wound stator[48 and an inductively coupled wound rotor 148, located within unit 22,the output of the channel being connected to energize a servo motor 38which connects through a clutch 3! with the aileron surface 24.Operation of motor 3i] displaces an inductive follow-up device 32developing a follow-up signal therein which is impressed upon the banksignal in the amplifier to modify operation of the motor In a similarmanner, as a result of a pitch condition, take-off 2T developes a pitchsignal which is communicated to the input of the elevator channel ofamplifier 18 through an inductive pitch receiver device 33, comprising awound stator I and an inductively wound rotor Hit likewise locatedwithin unit 22, the output of the pitch channel being connected toenergize the servo motor 34 which connects through a clutch 35 withelevator surface 25, the operation of the motor displacing an inductivefollow-up device 36 developing a follow-up signal therein which isimpressed on the pitch signal in the amplifier to modify operation ofmotor 34.

Coming now to the automatic turn control mechanism and the novel controlunit constituting the subject matter of the present invention, thelatter is shown schematically in Figure 2 as embodying an inductive bankdevice 225 having the wound stator I46 of Figure 1 and the inductivelycoupled rotor I48 carried by a shaft 226, an inductive rate device 221having the wound stator I30 of Figure 1 and the inductively coupledrotor I32 carried by a shaft 228, and an inductive pitch device 229having the wound stator I85 of Figure 1 and the inductively coupledrotor 18! carried by a shaft 230.

For the purpose of displacing rotor 181 of the pitch device 229 relativeto its stator 180 to thereby generate a signal for energizing theelevator servo motor 34 for displacing elevator 25 to trim the craft inpitch, a pitch trim knob 23! is provided on a shaft 232 having a pinion233 for engagement with a relatively large gear 234 sleevedloosely on aturn shaft 235. Gear 234 is provided with two toothed hubs 236 and 231,the latter engaging a gear 238 which is in mesh with a gear 239 having amarker thereon (not shown) for cooperation with a fixed index (notshown) to designate the instantaneous position of rotor 18! while theformer meshes with a large gear 240 carrying a pinion 24! for meshingwith an idler 242 which, in turn, drives a differential comprising agear 243, sleeved on rotor shaft 230, having a gear 244 in mesh with agear 245 journalled by a shaft 246 within plates 241, 248 of thedifferential, the plates being secured together by bolts 249 to define acage. Gear 245 meshes with a gear 250 which is supported by a shaft 25!journalled within plates 241, 248 and which, further, meshes with a gear252 pinned to rotor shaft 233. Thus, angular displacement of pitch trimknob 23l ultimately resolves itself into angular displacement of rotorI81 in either direction whereupon signals are developed therein andcommunicated by way of leads I82 to the input of amplifier [8 forenergization of motor 34 of the elevator servo system.

For the purpose of displacing rotor I42 of the bank device 225 relativeto its stator 145 to thereby generate a signal for energizing theaileron servo motor 30 for displacing aileron 24 to trim the craft inbank, a bank trim knob 253 is loosely sleeved on turn shaft 235 and isprovided with a pinion 254 which is in engage ment with a gear 255fastened to rotor shaft 225. By manipulating knob 253, therefore, rotor148 is displaced directly relative to its stator whereupon signals aredeveloped in the rotor and communicated by way of leads 149 to the inputof amplifier l8 for the energization of motor 33 of the aileron servosystem, it being noted that in both cases pitch and bank signals aredeveloped at the panel independently of the gyro horizon or masterinstrument 28.

In order to place a craft provided with the all electric, automaticpilot hereinabove described into an automatic turn, turn shaft 235 isprovided with a turn knob 256, the shaft, in turn, having fastenedthereto a gear 251 which is in engagement with a relatively large gear258 loosely sleeved on shaft 223. Gear 258 connects with shaft 226through a slip clutch comprising a clutch face 259 carried by the gearand a cooperating clutch face 260 pinned to shaft 226 and urged intofrictional engagement with face 253 by way of a spring member 261resting between face 263 and a fixed disc 252 fastened to the shaft.Angular displacement of turn knob 256 manifests itself in angular motionof rotor 148 relative to its stator through gears 251, 258, clutch 259,230 and shaft 225, motion of the latter causing bank trim knob 253 tofollow motion of turn knob 256 by virtue of gears 254, 255.-

In addition to the bank signal, the proper rudder and elevator signalsare likewise set in by turn knob 255, the rudder signal bein derivedfrom the inductive rate device 221 which is connected through anadjustable air speed linkage with bank device 225 and the up-elevato-rsignal being derived from the pitch device 229 which is connectedthrough the differential with the rate device 221.

Motion of gear 258 as a result of the displacement of turn knob 256resolves itself into motion of a gear 253 sleeved on an air speedadjustment shaft 255, the hub of gear 233 being yieldably urged intoengagement with the hub 265 of a lock member 265 which is normallylocked by way of a screw 251 to shaft 264. Motion of gear 253,therefore, is translated into movement of shaft 255 whose free end hasfastened thereto a gear 258 adapted for driving a relatively large gear259 which supports at its center by way of a bracket 218 a shaft 211carrying a gear 212 which meshes with an internal gear 213,1 the outerperiphery of the latter being toothed for driving engagement with apinion 214 fastened to the free end of turn shaft 235. Assuming properair speed adjustment, motion of turn knob 258 causes rotation of gear258 and pinion 214 whereby both gear 252 and internal gear 213 movetogether so that a pin 215 secured by a bracket 215 to gear 212 moves inan arc and by so doing angularly displaces a lever 211 about a pivot218, the lever having a relatively long slot 219 for cooperation withpin 215. Movement of lever 211 about pivot 218 produces up or downmotion of a link 280 which connects with one end of a crank arm 281fastened to rate rotor shaft 228, the remaining end of crank 28l havinga link 232 secured thereto. By virtue of the foregoing connection, rotor[32 of inductive rate device 221 is displaced angularly relative to itsstator whereupon signals are developed in the rotor and communicated byWay of leads I33 to the rudder channel of amplifier 18.

As crank arm 28! is pivoted by link 28!! to displace rotor !32 it alsoactuates link 282 whose free end is pivotally connected to a link 283which is pivotally secured at 284 to plate 243 of the pitchdifferential. Inasmuch as link 223 is connected to one side of plate 243and is also engaged by a pitch cam system to be presently described,movement of link 282 to the left or right will inanifest itself in aclockwise rotation only of plates 241 and 248 and since gear 243 islocked at this point, gear 245 will creep on gear 244, which is nowfixed, to rotate gear 252 and angularly displace rotor 18! through gear250 so that for either left or right turn an up-elevator signal will begenerated and communicated by way of leads I82 to the elevator servochannel of amplifier 18.

In addition to gears 251 and 214, turn shaft 235 also carries a notchedmember 235 within arm, provided iwithza. contact (not shown) is :moveddownwardl i.tonopenra pair ofconta'cts (not I shown) arranged .within .aconventional switch ,box: 29fl which; normally connect a .coil

. ifi'iofithe magnetic clutch 'i'llatrthec master indicator .withabatteryrSB. -.Opening of-thecontacts by angular; displacement:- of. the;turn shaft,

therefore, de-energizes coi1 6'l.-so::that thedirec tion signal: fromthe inductor compass -:is ,-discon- 'nected during ."a turn from therudder reserve channel.

' If it; is desired tog-.adjustithe airspeed .linkage result or which.gear12 69 ;.is idisplacedrelative; to internalgear2.'I3..which:gis"'held fa'stvby gear; 214, itszshaft 235 :beinglocked: by detent: 286, whereupon gear 212- creeps within: the internalgeargto displace pin 275 linearly relativeto slot 219, of lever 21?.This adjustment; .therefore,:.;determines the ,amount of motion;oflever21I and rate rotor "132 for a given, setting of turn.;knob 256,;the

pin 275 being positioned for cruising-speeds, sub stantially as shownin'FigureZHand it. iszmoved inwardly for increasing .air speeds so thatfor :ex-

tremely high speeds little or no displacement is :obtaine'dpn thepart-ofrotor I32.

-A novel zadjustment:,;is also providedrrin the nature of a pitch camsystem generallydesignated with the character 29! to insure properinitial settingof link 282zwhereby for given rates of turn in either aleft or'ri'ght direction enough displacement of vrotorI'8I'-. will be.provided to maintain the craft in'level attitude-during turn, i.-e., topreventa'nosej-heavy or loss ofaltitude condition during a given turn.To. this end, therefore, link 2 82' is provided with a' roller 292-which engageswith a'pair of cams.-:29 3,; 294, the former being fixed toa shaft295, anduthe latterbeing hollow ,and sleeved on; the shaft andprovided with-a gear 296 forcmeshing-with arpinion 29? carried by asecond; and'parallel shaft 298. Ad-

justment of the two cams defines the limit of downward throw ofroller292 for a, given left'or rightmotion of link 282 and consequently theamount of. displacement of; rotor I8! fora given set turn. Shafts-2951and298 are provided at their free ends with collars 299 havinglugsnormally: yieldably urged intoengagement with. longitudinally movablecones 300 engagedby adjusting screws 30!. The screwsareaprovidedzwith,.:straps 382 which normally, lock screws 1130i in agiven position butupon looseningof other screws, 303,

theystrapsare: actuated to unlock screws 30! and adjustment thereof willurge the I cones relative to, the lugs whereby shafts 295and 298 aredis- ;placed angularly to set cams'293, 294 asdesired.

'- isshown in Figures .3" and. 4 and as .therev illustrated, a" housing3 I B is provided :for enclosing It will now be readily apparentto,those-skilled in. the art thatby operating'turn knob 256 bank, rate andpitch. signals aredeveloped in inductive devices 225, 221' and. 229-independently of ;.-their respective master instruments aileron,rudderand elevator. surfaces aredeflected the properamount toplaceztheicraft in a turn whereby the attitude, surface deflection continuinguntil the follow-back signals of...inductive devicesr23, 32 and. 36(Figure l). are equal andopposite to the .bank, rate and pitchsignals'of-idevices';225,?22i

and. 229. Asfithecorrect'cra'ft attitudev is at- .tained, signalsaregeneratedtbyithemaster instruments, i. e.,-rateutake-off I2 and: thebank i: 22 9. 'Therfolloweback. signals; at this point; being ata'maximum-act alone-.inireversing servo motors'i 9 ,23iland34 to centergthe'rudder, aileronand elevator surfaces," the craft'remaining in. the;desired banked attitude. Moreover, should the craf t Once the newcourseis attained,

craft on the new course and switchZtd isclosed to energize coil 67 ofclutch; llithezmastergindicator whereby the compass takesover andmain-"tains control of the rudder.

One practical embodiment: of a 1 control panel for controlling the novelmechanism oi -Figure 2 the. mechanism of Figurezwhich is supported by acasing (not shown) arranged within the hous= ing and having a'flange 3 II provided witl1:open- -ings 3i2 for securing theunit to the craft. lKFCLS- tenedto the-irontof flange' 3H is a substantially annular and hollowmember3l3 accommodating therein the pitch trim knob3i4 correspondingt0knob 23i of Figure -2. Member 3131s provided with two removable caps'3i5 andf3l6 whichrcover respectively, the free end of air speedadjustment shaft 264 of Figure 2 and the screwsrSilI andjfiii of -thepitch cam system 29L Inscribed on member3l3, "furthermore, is::a fixedreference marker 3 I 'I' :with which cooperates a pitch marker 3 I 8carried byan angularly movable disc 3i9 fastened .togear 239 of FigureThus-angular motion of pitchtrim knob 3 I 4 provides angulardisplacement in either; direction of pitch rotor I8! of'Figurexz'through gears;233, 234, 23%;, 240, 2 1L242; 243 andv 244-452ands-imu-ltaneously through gears;23l;.23il and 2391displaces marker 3|8 relative to markerj fll' to indicate the displacement'from nullpofthe,pitch rotor.

Superimposed over member "'3I3: is the; bank trim knob 320 havinga-knurled'periphery, the knob corresponding to a bank trim knob 253::of'Figure 2, the major portion of :knob -'32B';bil'lg provided withashield "321 secured to member 3I'3. Arranged on memberal3isgapin'322whose front end defines a fixed marker or; referenceagain'stwhich trimknob 320 is operated, the latter knob having a marker323 thereon which, when alignedwith pin 322,. indicates that rotor I48of bank device 225=is ata'normally mull position. Moreover, knob 320.may-beprovided to inform thepilot of the direction:v of the.

322. Angular displacement of bank knob 329, as explained inconnection:with knob253v of Figure 2, displaces rotor idilofrbankdevice"2251;directly in either direction byway-of gears 5254 and 255.

A turn knob 324, corresponding: to turn. knob 25S of'Figure 2, issuperimposedovenbank; trim knob 32! and is .providedwithiajreferenceflline 325 thereon. which, when aligned: with markers322and -323, indicates the craftstobe in straight flight. "-The lowerend. of "knob 1324 is. provided with a: stop member 1326.; adapted :forlimiting angular movement of the knob by engagement with either of limitpinsi32'bor' 328carried on bank knob'320. Displacement of turn knob 324to the right or left of marker:pin.322 results in motion of shaft 235:of. Figure. 2 aswell as gears 251 and'258 to'displace rotor. I48; ofthe-:zbank *deviceand shaft 264 of..the;airspeed .linkagadisplacement ofshaft 226 resulting in displacement of gears 254, 255' whereby bank trimknob 32!! follows motion of the turn knob. Simultaneously, gear 214 onthe turn shaft is rotated to turn internal gear 213 whereby rotor 132 ofthe rate device 221 is displaced angularly through the airspeed linkageand rotor [8! of pitch device 229 is displaced through the pitch camsystem 29!. In addition to the foregoing displacements resulting inmaneuvering the craft into a turn, operation of knob 324 results in theopening of switch 290 whereupon the compass system is disconnected fromthe rudder servo channel of ampliiier I8 as heretofore explained.

The novel automatic turn control mechanism including the compact panelarrangement therefor is of such a character that extreme flexibility ofcontrol is provided by the automatic pilot which makes it possible toexecute maneuvers by turning appropriate controls on the panel. Sharplybanked turns may be made by actuation of turn control knob 324, thecraft immediately returning to straight flight when the knob is returnedto its central position, Bank and pitch trim is immediately availableupon operation of knobs 328 and 3M. Steep climbs or dives may be made byoperating pitch trim knob 3. Moreover, a combination of turns and climbsor turns and dives may also be executed or the craft quickly thrown froma correctly banked turn in one direction to a correctly banked turn inan opposite direction.

' Although but a single embodiment of the invention has been illustratedand described in detail, it is to be expressly understood that theinvention is not limited thereto. Various changes may also be made inthe design and arrangement of the parts without departing from thespirit of the invention, as the same will now be understood by thoseskilled in the art.

I claim:

1. In an automatic pilot for aircraft having rudder, aileron andelevator actuating motors and master instruments for normally operatingsaid motors, a control panel for said pilot, means mounted on one sideof said panel and interconnected with one of the master instruments andthe rudder motor so as to normally have a signal reproduced thereinproportional to the turn by said shaft from a prescribed direction foroperating said rudder motor, means mounted on said one side of saidpanel and interconnected with the other of the master instruments andthe aileron and elevator motors so as to have signals normallyreproduced therein proportional to the bank and pitch of said craft whensaid craft departs from a prescribed attitude for operating said aileronand elevator motors, an airspeed linkage interconnecting said bank andturn signal reproducing means, means comprising a differentialinterconnecting said turn and pitch signal reproducing means, and a turncontrol on the opposite side of said panel drivably connected with saidbank signal reproducing means for simultaneously actuating said turn,pitch and bank signal reproducing means for generating signals foroperating said rudder, aileron and elevator motors independently of themaster instruments.

2. In an automatic pilot for aircraft having rudder, aileron andelevator actuating motors and master instruments for normally operatingsaid motors, a control panel for said pilot, means mounted on one sideof said panel and interconnected with one of the master instruments andparts from a prescribed attitude for operating said aileron and elevatormotors, a linkage interconnecting said bank and turn signal reproducingmeans, a difierential mechanism interconnecting said turn and pitchsignal reproducing means, a turn control on the opposite side of saidpanel drivably connected with said bank signal reproducing means for.simultaneously actuating said turn, pitch and bank signal'reproducingmeans for generating signals for operating the rudder, aileron andelevator motors independently of said master instruments, and a pitchtrim control on said opposite side of said panel drivably connected withsaid pitch signal reproducing means for overriding the control of thelatter by said turn control.

3. In an automatic pilot for aircraft having rudder, aileron andelevator actuating motors and master instruments for normally operatingsaid motors, a control panel for said pilot, means on one side of saidpanel interconnected with one of the master instruments and the ruddermotor so as to have a signal normally reproduced therein in proportionto the turn of said craft when said craft departs from a prescribedcourse for operating said rudder motor, second and third means on saidopposite side of said panel interconnected with other of the masterinstruments and the aileron and elevator motors so as to have signalsnormally reproduced therein in response to the bank and pitchrespectively of saidcraft due to its departure from a prescribedattitude for operating said aileron and elevator motors, a pitch trimknob on the opposite side of said panel for actuating said pitch signalreproducing means to trim the craft in pitch, .a bank trim knob on saidopposite side of said panel for actuating said bank signal re producingmeans to trim the craft in bank, and a turn knob aligned with andsuperimposed over said bank trim knob for simultaneously actuating saidturn, bank and pitch signal reproducing means for generating signals foroperating said rudder, aileron and elevator motors independently of themaster instruments.

4. In an automatic pilot for aircraft having rudder, aileron andelevator actuating motors and master instruments for normally operatingsaid motors, a control panel for said pilot, means on one side of saidpanel interconnected with one of the master instruments and the ruddermotor so as to have a signal normally reproduced therein in proportionto the turn of said craft when said craft departs from a prescribedcourse for operating said rudder motor, second and third means on saidopposite side of said panel interconnected with the other of the masterinstruments and the aileron and elevator motors so as to have signalsnormally reproduced therein in response to the bank and pitchrespectively of said craft due to its departure from a predeterminedattitude for operating the aileron and elevator motors, a bank trim knobon said opposite side of said panel for actuating said bank signalreproducing means to trim said craft in bank, means including. a turnknob alignedtwith-andcsuperiinposed over said bank trim; knobs forsimultaneously actuating said,

turn, bank and pitch signal reproducing means forgenerating signals. foroperating said rudder, aileron and elevators motors independently ofthe. master 9instruments,.-a pitch trim knob on said-oppositesideof-said panel for actuating saidrpitch-tsignal reproducing meansindependently of said,turn-knob,--and an indicator on saidpanel-operable bysaid pitch trim knob.

55 A control unit-for an aircraft automatic p-ilotjhavingrudder, aileronand elevator actuatingemotors togethenwith master instruments fornormally operating said lllOtOlS, comprising a casing; an inductive:turnsignal device-Withinsaid. casing for: opera-tingsaidrudder motorindependently ofits. related master instrument, aninductive banksignal.device within said casing for operating said aileron motor independently of. itsrelated masterinstrument, an induc-- tive .pitch signal.device within said casing for operating said elevator motorindependently of its-relatedmaster instrument. an airspeedlinkageinterconnectin g. saidturn and .bank devices, a .differentialmechanism. interconnecting said turn and ,pitchdevices. andiauturncontrol knob exterior. of said casing. vdrivably connected withsaidbankdevice.foractuating said bank, turn and .pitch. devicessimultaneously.

6. A .control.,unit..for,- an aircraft automatic pilot having rudder,aileron. and elevator actuatingmotors togetherwithmaster instruments fornormally operating, saidimotors comprising a,

casing,,an inductive turn signal device within said. :casing.forloperating said. rudder motor independently of its relatedmasterinstrument, an inductive. banksignal device within said casing foroperating. said. aileron ,motor. independently of itsrelatedlmaster,instrument, an inductive pitchsignal device-withinsaidcasing. for operatingsaid elevator motor. independently of its relatedmaster, instrument, an airspeed linkage interconnecting said turn andbank devices, a differential. mechanism interconnecting said. turnandpitch devices, a bank trimknob exterior of-saidfcasingand .drivablyconnected to said bank device for.the actuation thereof, a turn controlknob .exterior of said casing, and means including a friction clutchdrivably connecting.

said, turnknobwith. saidbank device whereby in response to. theoperation of said turn knob said bank, turn and .pitchdevices as well assaid bank trimknob are actuated.simultaneously.

'lLA' controlunit' foran aircraft automatic pilot ,having rudder,aileron and elevator actue ating .motors together with masterinstruments for normally.v operating said motors, comprising a casin.inductive bank, turn and. pitch signal devices within said casingqforactuating said rudder, aileron and. elevator motors independentlyoftheir related master instruments, an air speed linkage interconnectingsaid turn and .bank devices, a differentialmechanism interconnecting.said. turn and pitch. devices, a turn control restrict rotation ineither direction of said knob...

8, A control unit for an aircraft automatic pilot having, rudder,aileron and. elevator .actuat-I ing .motors together with master.instruments for normally operating said "motors, comprising. a.cas-.

inc: and a-icontrol panel attached thereto, in. ductive bank, turn andpitch devices within said, casing for operating said ,rudder, aileronand elevator motors independently of their related, master. instruments,pitch. trim and. bank trim knobs on. said. panel connected, withsaidpitch and bankdevices, and a turn knob on said panel, coaxial with,and: superimposed over said bank, trim knobifor actuating said bank,turn and pitch devices simultaneously;

9.; A- control unit for an aircraft automatic pilot having rudder,aileron and elevatoractuating-motors together; with master. instrumentsfor normally operating -said motors, comprising. a casing and a controlpanel attached thereto,- inductive bank, turn ,and pitch devices Within.said casing for operating said. rudder, aileron and. elevator. motorsindependently of their related. master instruments, a v bank-trim. knobon said panel and drivably connected with. saidv bank device fortheactuation thereof, a turn knob. on, said panel coaxial, with. andsuperimposed, over said banktrimknob, means comprising a, frictionclutch for, drivably connectingsaidturn. knob with said bank. devicewherebyupon actuar tion, of said .tur-n knobsaid ,bankndevice is voper:ated,.and.means interconnectingsaid bankdevice with said turnandpitchdevices. for simultaneous .operationwith, said, bank, device.

10. In a control unity for. an. aircraft automaticpilot having rudderandaileron.actuating motors, and masterinstruments fornormally-operating. said motors, the combination with abank in-. ductivedevice and, a. turn, inductive device for actuating said aileron andrudder motors, rESpeC? tively, independently ,of their related masterinstruments, of an airspeedlinkage for connecting. saidbank inductivedevice with said turn inductive device comprising, adslottedpivotedleveroperativelyconnected.to. said turn inductive device, meanscomprising. apin for cooperation with theslot of saidlever, and meansf0r actuating said. banks. inductive. device and simultaneously said pintoioscillate said lever to thereby operate said .turn inductive device.v

11. In acontrol unit for an aircraft automatic pilot having rudder andaileron actuating motors and master instrumentsfor normally operating,saidmotors, thecombination with a bankinductive device. and aturninductive device foractuating said aileron and rudder. motors,respectively, independently of their related master instruments, of anairspeed linkage for connecting.

said, bankinductive device with .said turn inductive device comprising,.a slotted pivoted lever operatively connected to said turn inductivedevice, means comprising a pin for cooperation with the slot of saidlever, meansincluding an internal gear for operatingsaid pin tooscillate said. lever to thereby operate said turn inductive device,andmeans .for actuatingsaid bank in: ductive device and;said internalgear whereby said turn inductive device is operatedsimultaneously withsaid bank-inductive device.

12. In a control unit. for an aircraft automatic pilot having rudder andaileron actuating motors and master instrumentsfor normally operatingsaid motors, thecombinationwitha bank inductive device and a turninductive device for actu-v atingthe aileron and ruddermotors,respectively,v independently, of their related master,instruments, of an airspeed linkage, for connecting said bankinductivedevice with saidturn inductive device comprising, a slotted andpivotally mounted lever operatively connected" to said turn inductivedevice, a pin arranged in the slot of said lever to oscillate said leverto thereby actuate said turn inductive device, means comprising aninternal gear for operating said pin to oscillate said lever, means foractuating said bank inductive device and said internal gear, and meanssupporting said pin and adapted to move said pin relative to said gearand said slot to thereby vary the oscillation of said lever for a givenoperation of said bank inductive device.

13 In a control unit for an aircraft automatic pilot having rudder andaileron actuating motors and master instruments for normally operatingsaid motors, the combination with a bank inductive device and a turninductive device for actuating the aileron and rudder motors,respectively, independently of their related master instruments, ofanairspeed linkage for connecting said bank inductive device with saidturn inductive device comprising, a slotted and pivotally mounted leveroperatively connected to said turn inductive device, a pinarranged inthe slot of said lever to oscillate said lever to thereby actuate saidturn inductive device, a gear supporting said pin, means comprising aninternal gear in engagement with said last-named gear to actuatesaidpin, means adapted to move said supporting gear relative. to saidinternal gear to thereby move said pin relative to said slot to vary theoscillation of said lever for a given operation of said bank inductivedevice, and means for actuating said bank inductive device and saidinternal gear.

14. A control unit for an aircraft automatic pilot having rudder andaileron actuating motors and master instruments for normally operatingsaid motors, comprising a casing and a control panel attached thereto,inductive bank and turn devices within said casing for actuating saidmotors independently of their related master instruments, a linkageconnecting said bank device withsaid turn device and comprising aslotted and pivotally mounted lever operatively connected to said turndevice, a pin cooperating with the slot of said lever, means foractuating said pin to oscillate said lever, means for variablydisplacing said pin relative to the slot of said lever to thereby varythe lever length of the latter. an airspeedadjustment on said panel foroperating said displacing means, and means comprising a turn control onsaid panel for simultaneously operating said bank device and said pinactuating means.

.1 5, ,A control unit for an aircraft automatic pilot having rudder andaileron actuating motors and: master instruments for normally operatingsaid motors, comprising a casing and a control panel attached thereto,inductive bank and turn devices within said casing for actuating saidmotorsv independently of their related master instruments a linkageconnecting said bank device with said turn device and comprising aslotted and pivotally mounted lever operatively connected to said turndevice, a pin arranged in the slotof said lever to oscillate said leverto thereby actuate said turn device, a gear for supporting said pin,means comprising an internal gear in engagement with said last-namedgear to actuate said pin, normally locked adjustment means connectedwith said supporting gear and adapted to move the latter relative tosaid internal gear to thereby move said pin relative to said slot tovary th e oscillation of said lever for a given operationeof saidbankdevice, anfairspeed adjustment on said panel for operating saidadjustment ating motors and master instruments for nor-' mally operatingsaid motors, comprising a casing and a control panel attached thereto,inductive bank, turn and pitch devices within said casing for actuatingsaid motors independently of the related master instruments, a linkageinterconnecting said bank and turn devices, a differential mechanismconnected with said pitch device, a link for interconnecting one side ofsaid differential mechanism with said turn device, cam means inengagement with said link to govern the motion of said link transmittedto said differential mechanism for a given operation of said turndevice, and a turn control on said panel drivably connected with saidbank device for actuating said bank, turn and pitch devices in unison.

17. A control unit for an aircraft automatic pilot having rudder,aileron and elevator actuating motors and master instruments foroperating said motors, comprising a casing and a control panel attachedthereto, inductive bank, turn and pitch devices within said casing foractuating said motors independently of their related master instruments,a linkage interconnecting said bank and turn devices, a diiferentialmechanism connected with said pitch device, a link for interconnectingone side of said differential mechanism with said turn device, cam meansin engagement with said link to govern the motion of said linktransmitted to said differential mechanism for a given operation of saidturn device, adjustment means on said panel for presetting the positionof said cam means relative to said link, and a turn control on saidpanel drivably connected with said bank device for actuating said bank,turn and pitch devices in unison.

18. A control unit for an aircraft automatic pilot having rudder,aileron and elevator actuat-.

ing motors and master instruments for normally operating said motors,comprising a casing and a control panel attached thereto, inductivebank, turn and pitch devices within said casing for actuating saidmotors independently of said master REFERENCES CITED The followingreferences are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 4 Fischel Nov. 22, 1938 7 CarlsonJune 11, 1940 2, 01,354 Holt June 4, 1946 Carlson May 25, 1948Certificate of Correction July 25, 1950 Patent No. 2,516,641

NORMAN B. MURPHY It is hereby certified that error appears in the printenumbered patent requiring correction as follows:

Column 7, line 50, for the Word shaft read craft; and that the saidLetters Patent should be read as corrected above, so

of the casein the Patent Ofiioe.

may conform to the reco Signed and sealed this 14th day of November, A.D. 1950.

d specification of the above that the same THOMAS F. MURPHY,

Assistant Commissioner of Patents.

Certificate of Correction Patent No. 2,516,641 July 25, 1950 NORMAN B.MURPHY It is hereby certified that error appears in the printedspecification of the above numbered patent requiring correction asfollows:

Column 7, line 50, for the word shaft read craft; and that the saidLetters Patent should be read as corrected above, so that the same mayconform to the record of the casein the Patent Ofiice.

-Signed-and sea1ed this 14th day of November, A. D. 1950.

THOMAS F. MURPHY,

Assistant Commissioner of Patents.

